No there was nothing missing. Distro 20.04 has installed all :i386 libs needed for the wine32- and wine64-bridges. Also I've set the "dpkg --add-architecture i386" befor and installed the "build-essential".
I installed the Bridges with: apt-get install carla-bridge-wine32 carla-bridge-wine64 Weeks ago I had installed a "Ubuntu Studio 20.04 beta" and did not have these problems. Maybe that helps. Know I solved this problems with recompiling the carla-bridge-wine32 and carla-bridge-wine64 by installing the carla build dependencies with: apt-get build-dep carla Then I removed all distro packages from wine-development* (5.5) and installed version 5.7~focal form WineHQ: wine-devel wine-devel-dev wine-devel-amd64 wine-devel-i386:i386 and compiled without any error: make win32 CC=i686-w64-mingw32-gcc CXX=i686-w64-mingw32-g++ make win64 CC=x86_64-w64-mingw32-gcc CXX=x86_64-w64-mingw32-g++ make wine32 && make wine64 Did you have the Harrison AVA-legacy-EQ (Win VST3/32)? There you can see the analyser is missing in the top. The Knobs are visible in the lower part of the plugin. (OpenGL overlay?) The older Version of Limiter No.6 (Win VST2/32) shows only a black screen. (Not the known BUG with Limiter No.6. I have the working Version) Aamazingly, carla now also works from distro 20.04 including the both 32/64 wine-bridge together with the new packages from "WineHQ Wine-Devel 5.7~focal" installed. It looks like the "wine-development" packages have changed since beta?!? -- You received this bug notification because you are a member of Ubuntu Studio Bugs, which is subscribed to carla in Ubuntu. https://bugs.launchpad.net/bugs/1875641 Title: Wine32 VST Bridge plugins missing gui (Ubuntu Studio 20.04) Status in carla package in Ubuntu: New Bug description: Carla works very well with the Wine64 Bridge. Only the Wine32 starts the VST32 Plugins in a Window with a black screen with the NVIDIA- Meta-Driver-440. I've uninstalled the wine-development version 5.5 and installed the latest winehq-devel 5.7 from WineHQ and recompiled the Carla-Bridges my self. Now the Wine32 VST Plugins are working. Maybe it's a bug in the wine-development package or something missing in the carla package. --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: XFCE DistroRelease: Ubuntu 20.04 InstallationDate: Installed on 2020-04-25 (3 days ago) InstallationMedia: Ubuntu-Studio 20.04 LTS "Focal Fossa" - Release amd64 (20200423) NonfreeKernelModules: nvidia_modeset nvidia Package: carla 2.1-0ubuntu1 PackageArchitecture: amd64 ProcVersionSignature: Ubuntu 5.4.0-26.30-lowlatency 5.4.30 Tags: focal Uname: Linux 5.4.0-26-lowlatency x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm audio cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/carla/+bug/1875641/+subscriptions -- Mailing list: https://launchpad.net/~ubuntustudio-bugs Post to : [email protected] Unsubscribe : https://launchpad.net/~ubuntustudio-bugs More help : https://help.launchpad.net/ListHelp

